Taking Octamop Tablet (Methoxsalen 10 mg) long-term, such as for 5 years, can be effective for conditions like vitiligo or psoriasis, but it also carries certain risks. Prolonged use may increase the chance of skin cancer, cause premature skin ageing, and affect the eyes if proper protection is not used. The drug also makes the skin highly sensitive to sunlight, so precautions such as sunscreen and protective clothing are essential. With regular medical supervision, monitoring, and sun protection, Octamop can be used safely, but a doctor should carefully evaluate long-term therapy.